[PATCH v2 02/10] pylibfdt: Add subnode/property iterators and get_mem_rsv_list()

[Douglas Anderson <dianders@chromium.org>]

Add Pythonic iterator helpers on `FdtRo` to simplify walking nodes,
properties, and memory reservation entries without manual offset loops
or `-FDT_ERR_NOTFOUND` sentinel handling:

- `subnodes(nodeoffset)`: yields the offset of each direct child subnode
  of `nodeoffset`.
- `properties(nodeoffset)`: yields a `Property` object for each property
  of `nodeoffset`.
- `get_mem_rsv_list()`: returns a list of `(address, size)` tuples for
  all entries in the memory reservation block.

Assisted-by: Gemini:gemini-pro-prerelease
Signed-off-by: Douglas Anderson <dianders@chromium.org>
---

Changes in v2:
- New patch adding FdtRo.subnodes(), FdtRo.properties(), and
  FdtRo.get_mem_rsv_list()

 pylibfdt/libfdt.i       | 45 +++++++++++++++++++++++++++++++++++++++++
 tests/pylibfdt_tests.py | 18 +++++++++++++++++
 2 files changed, 63 insertions(+)

diff --git a/pylibfdt/libfdt.i b/pylibfdt/libfdt.i
index 46f28f67290d..0db7110b4a38 100644
--- a/pylibfdt/libfdt.i
+++ b/pylibfdt/libfdt.i
@@ -201,6 +201,23 @@ class FdtRo(object):
         """
         return check_err(fdt_next_subnode(self._fdt, nodeoffset), quiet)
 
+    def subnodes(self, nodeoffset):
+        """Iterate over the subnodes of a node
+
+        Args:
+            nodeoffset: Offset of parent node to check
+
+        Yields:
+            Node offset of each direct subnode in order
+
+        Raises:
+            FdtException on error (e.g. invalid nodeoffset)
+        """
+        soff = self.first_subnode(nodeoffset, quiet=QUIET_NOTFOUND)
+        while soff >= 0:
+            yield soff
+            soff = self.next_subnode(soff, quiet=QUIET_NOTFOUND)
+
     def magic(self):
         """Return the magic word from the header
 
@@ -302,6 +319,17 @@ class FdtRo(object):
         check_err(val[0], quiet)
         return val[1:]
 
+    def get_mem_rsv_list(self):
+        """Return a list of all memory reserve-map records
+
+        Returns:
+            List of (address, size) tuples for each memory reserve-map record
+        """
+        return [
+            tuple(self.get_mem_rsv(i))
+            for i in range(self.num_mem_rsv())
+        ]
+
     def address_cells(self, nodeoffset, quiet=()):
         """Return the number of address cells used by a node's children
 
@@ -434,6 +462,23 @@ class FdtRo(object):
             return pdata[1]
         return Property(pdata[0], pdata[1])
 
+    def properties(self, nodeoffset):
+        """Iterate over the properties of a node
+
+        Args:
+            nodeoffset: Offset of node to check
+
+        Yields:
+            Property object for each property on @nodeoffset in order
+
+        Raises:
+            FdtException on error (e.g. invalid nodeoffset)
+        """
+        poff = self.first_property_offset(nodeoffset, quiet=QUIET_NOTFOUND)
+        while poff >= 0:
+            yield self.get_property_by_offset(poff)
+            poff = self.next_property_offset(poff, quiet=QUIET_NOTFOUND)
+
     def getprop(self, nodeoffset, prop_name, quiet=()):
         """Get a property from a node
 
diff --git a/tests/pylibfdt_tests.py b/tests/pylibfdt_tests.py
index 1b65961491bf..2a0509c7802e 100644
--- a/tests/pylibfdt_tests.py
+++ b/tests/pylibfdt_tests.py
@@ -243,6 +243,22 @@ class PyLibfdtBasicTests(unittest.TestCase):
             node_list.append(self.fdt.get_name(node))
             node = self.fdt.next_subnode(node, QUIET_NOTFOUND)
         self.assertEqual(node_list, ['subnode@1', 'subnode@2'])
+        self.assertEqual(
+            [self.fdt.get_name(n) for n in self.fdt.subnodes(0)],
+            ['subnode@1', 'subnode@2'],
+        )
+        leaf = self.fdt.path_offset('/subnode@1/ss1')
+        self.assertEqual(list(self.fdt.subnodes(leaf)), [])
+
+    def testPropertiesIterator(self):
+        """Check that we can iterate through properties of a node"""
+        node = self.fdt.path_offset('/subnode@1')
+        props = list(self.fdt.properties(node))
+        self.assertEqual([p.name for p in props],
+                         ['compatible', 'reg', 'prop-int'])
+        self.assertEqual(props[0], b'subnode1\0')
+        leaf = self.fdt.path_offset('/subnode@1/ss1')
+        self.assertEqual(list(self.fdt.properties(leaf)), [])
 
     def testFirstNextSubnodeOffsetExceptions(self):
         """Check except handling for first/next subnode functions"""
@@ -410,6 +426,8 @@ class PyLibfdtBasicTests(unittest.TestCase):
         self.assertEqual([ 0xdeadbeef00000000, 0x100000],
                           self.fdt.get_mem_rsv(0))
         self.assertEqual([123456789, 0o10000], self.fdt.get_mem_rsv(1))
+        self.assertEqual([(0xdeadbeef00000000, 0x100000), (123456789, 0o10000)],
+                         self.fdt.get_mem_rsv_list())
 
     def testAddDelReserveMap(self):
         """Test that we can add to and remove from the memory reserve map"""
-- 
2.56.0.313.g2479322e68-goog